A two-level electrohydraulic supply for agricultural implements: Implementation on a tractor/planter system

Abstract

As global food needs grow and emission requirements tighten, there is a natural need for more efficient agricultural systems. One component of such a system is joint electric and hydraulic supply. Prior work by the authors proposed a highly energy efficient, two-tier electrohydraulic supply for tractor-implement systems. This system supplies the majority of power hydraulically in order to keep component costs low, then augments this base supply with electrically powered boost pumps to enable efficient operation. This work expands on the prior work by validating key assumptions made in its design and further confirming savings potential through experimental demonstration. The architecture is presented, along with two control schemes, one prioritizing minimization of systems-level losses, and one prioritizing minimization of component losses. The sizing approach for both control systems is presented and then applied to a reference tractor and planter. After this, the proposed system is implemented and tested on a full-scale reference machine setup in realistic field test conditions. Results are presented testing the effects of inlet pressurization on ePump efficiency, as well as the total system’s power consumption reduction potential. These tests demonstrate up to a 40% reduction in system power consumption compared to the baseline commercial solution to complete basic mission tasks.